A fuzzy control apparatus is provided with an input of a controlled variable from a controlled object, executes so-called modus ponens reasoning, and outputs a manipulated variable (a fuzzy-control output) to be applied to the controlled object. Fuzzy reasoning often is expressed by control rules ("If . . . , then . . . " rules) in an "If . . . , then . . . " format.
A fuzzy control apparatus is available in which the control rules can be changed by a manual or remote operation during execution (operation) of fuzzy reasoning. In a fuzzy control apparatus of this kind, there is the possibility that the fuzzy-control output will vary suddenly according to the content of a changed rule. When a fuzzy-control output undergoes a sudden change, there is the danger that the controlled object will be adversely affected.
In order to deal appropriately with a controlled object having a characteristic that differs depending upon state, and in order to raise the accuracy of control, a system which controls one controlled object by using a plurality of control apparatus has been proposed. In a control system of this kind, which control apparatus among the plurality thereof is to be given charge of controlling the controlled object is decided using an arithmetic expression that is expressed arithmetically, and a changeover is performed manually by an attendant.
However, in accordance with the arithmetic decision regarding the control apparatus to be put in charge and the changeover based upon this decision, it is difficult to arithmetically express, in accurate fashion, the timing at which the control apparatus is changed over, and to evaluate the timing. In addition, it is difficult to perform a highly accurate changeover.
Further, in a manual changeover performed by an attendant, a problem which arises is that reproducibility of changeover timing is poor and a variance develops in the results of control. For example, in a case where the operation of a moving object is controlled, a problem encountered is that smooth control of operation cannot be carried out. In addition, in a case where the manufacturing process of an article is controlled, a variance develops in the quality of the articles manufactured.